The Gossip Girl star has been given temporary sole legal and physical custody of son Hermes, eight, and five-year-old daughter Helena, and Giersch has been told to send them to Los Angeles from his home in Monaco to live with their mum.

The stunning development comes just days after the actress told People magazine that her ex had banned her from visiting their children until she handed over their U.S. passports to "a neutral person" over his fears Hermes and Helena were kidnapping targets.

Celebrating the news over the weekend (23May15), Rutherford's lawyer Wendy Murphy told, "We are ecstatic, and hopeful that Monaco will respect the California court's ruling and send the children home. It has long been our position that Monaco has no jurisdiction because Hermes and Helena, as American citizens, have an absolute right to live in their own country.

"If the citizenship shoe were on the other foot and these children were citizens of Monaco, I have no doubt the United States would respect their right to reside in Monaco.

"Monaco officials know that sending the children back to America is the right thing to do. I'm looking forward to the happy reunion of the children not only with their mother, but also with their country!"

The actress has been fighting to appeal a 2012 ruling that awarded Giersch custody of the kids after his U.S. visa was revoked.

She filed for divorce in 2009, when she was three months pregnant with Helena, and then found herself having to travel to France just to see her kids.

Following the news of her custody win over the weekend, family friend Kim Kardashian took time away from her wedding anniversary plans to tweet, "Wow!!!!! Congrats @KellyRutherford You deserve ever bit of this joy!!!!"